Corrugated metal pipe is widely used for underground drains, culverts and other pipelines. To facilitate pipe construction and flexibility, such pipe is often helically wound wherein the corrugations and lock or welded seam extend helically around and along the length of pipe. In the trade, such pipe is termed either spirally or helically wound corrugated pipe. In laying a pipeline comprised of such pipe, the lengths of pipe after forming are taken to the job site where they are joined together by large split bands having spiral or helical corrugations which bands are placed about the juncture of butting or overlapping adjacent pipe lengths. Brackets are secured to the ends of the split bands which are drawn together by bolts extending between the brackets, thereby forming a seal between adjacent pipe lengths.
Another method of forming a pipeline from pipe lengths having annular -- not spiral -- corrugations is to flare the ends of the individual lengths of pipe outwardly to form an end flange prior to transporting the lengths of pipe to the job site. Pipe with annular corrugations costs more to manufacture than pipe with spiral corrugations, but it can easily be provided with an end flange. At the job site, these flanged pipe lengths are then joined together by channel band couplers, such as that described in applicant's co-pending U.S. patent application, Ser. No. 428,263. While methods and apparatus have been developed by applicant for flanging a length of pipe having annular corrugations, such methods and apparatus are not suited for flanging a length of spirally wound corrugated pipe. Accordingly, the superior channel type coupler was not compatible with spirally wound corrugated pipe until the development of the method and apparatus for flanging a length of spirally corrugated pipe which is the subject of the parent application, Ser. No. 598,173.